Field of the Invention
CPC fields: L2501/14, B37/60, B27/00
The disclosure relates to the field of flash steam generators for use within portable steam cleaning devices for both domestic and commercial use.
Description of the Prior Art
Portable steam cleaning devices are used for cleaning a variety of surfaces including floors, countertops, stovetops, tiles, glass, ceramic, clothing and upholstery. The application of high temperature steam can provide the requisite energy and solvent to solubilize greases, stains, dirt, odors, and other difficult to remove contaminants, which can then be removed by wiping or vacuuming. Steam cleaning devices may even be used to remove paint and wallpaper. Furthermore, the steam cleaner can effectively sanitize surfaces by killing dust mites, bacteria, and other pests without the need for chemicals, which makes it an ideal cleaning device for hypoallergenic environments.
While steam cleaners have been used for cleaning purposes for decades, portable steam cleaners have been relatively limited in functionality. There are two types of steam generators used in hand-held steam cleaners: 1 boiler chambers with a heating element to convert a reservoir of water to steam within the boiler, and 2 flash-steam generators that typically utilize a non-ferrous metal sandwich or heating block with internal paths to transport water as it is converted into steam by a heating element cast in the center plate.
Boilers have many disadvantages. They have a long start-up time due to the significant energy needed to heat up a large volume of water in the boiler chamber. Boilers are also heavy and space consuming. Because of its heavy and bulky nature, a boiler is located in a housing sitting on the ground instead of in the hand-held nozzle that is used to dispense steam. Finally, the steam generated in the boiler experiences a loss of heat energy as it travels from the boiler through the hose and out the nozzle, resulting in reduced cleaning capacity.
Flash steam generators are able to generate steam more quickly than boilers because they heat a small volume of water as it flows through paths that wrap around the outside of a heating block or through internal paths located within the heating block. This design allows flash steam generators to be smaller than boilers, which makes them amenable to being disposed in the hand-held nozzle for steam generation immediately before steam is dispensed. Thus, flash steam generators lose comparatively less steam heat and pressure than boilers. However, the current portable flash steam generators still produce relatively weak steam due to the lack of sufficient heat transfer. This limitation can be attributed to a combination of: 1 the low ratio of surface area contact between the water and the heating block relative to the flow volume, and 2 a water flow path that is too short to sufficiently heat the water.